Why spend money on expensive energy bars when you can make this easy low carb protein bar recipe with only 5 simple ingredients? These peanut butter protein bars are chewy and fudgy yet they stay firm at room temperature. The recipe is sugar free, low carb, gluten free and Keto.
Shop-bought low carb protein bars
I get it. Shop-bought low carb protein bars are suuper convenient. But they often come with a hefty price tag. Plus, many contain additives to extend shelf life, questionable sweeteners and inflammatory vegetable oils. And while they do solve an immediate problem (=hunger), I've never sampled one that actually tastes GREAT.
Easy Keto protein bar recipe
With a teeny-tiny bit of planning ahead, you can make absolutely DELICIOUS FUDGY, CHEWY peanut butter protein bars at home. They'll boost your energy after a workout and they're a fat-fuelled, protein-rich snack if you simply need a pick-me-up in between meals.
The main ingredient of this healthy Keto protein bar recipe is peanut butter. Peanut butter already has a high protein content, which I'm boosting with additional protein powder. I never add protein powder to my smoothies (I prefer straight-low carb granola, up veggie smoothies such as this detox Keto green smoothie). But I do like to add a scoop to my granolas because it helps to add extra crunch - check out this the crispy clusters are to die for.)
I experimented quite a bit with this recipe, because originally I wanted to create a no-bake protein bar. The problem with this was that no mix was sufficiently firm at room temperature whilst still fudgy and chewy. I did not want to coat the whole bar in chocolate only to get around that issue.
The solution? 25 minutes in the oven. Yes, a lil' bit of baking produces absolutely awesomely healthy protein bars that you can carry around all day in your handbag until hunger strikes!
How to make low carb peanut butter protein bars - step by step:Â
1.) Put the ingredients for the base and the top layer in separate bowls. I decided to use a brown sugar alternative to sweeten, but any granulated erythritol will work.
Your peanut butter should be EASY TO SCOOP. Give it a good stir if necessary - especially in larger pots it tends to settle on the bottom.
2.) Mix your ingredients with a fork and knead with your hands until you have a smooth dough.
3.) Grab yourself an oven-safe container. The mixture will fill a space of 5 x 6 inches. Your dish is larger than that? No problem. Simply fold a bit of aluminium paper and use it as a separator. That way, you can use only part of your casserole dish. The mixture does not spread.
Line the space with parchment paper and fill in first the peanut layer, then the chocolate peanut layer. Or do it the other way around 🙂
4.) After 25 minutes of oven time the bars are ready. This is what you should look out for: The top does not glisten any more. It has set and the edges are beginning to brown.
Wait until your low carb protein bars have cooled down before you cut them. They will be fragile and soft while hot, but firm up as they cool down.
Healthy peanut butter protein bar ingredients
There are plenty of peanut butter protein bars out there that use oats to thicken. I chose coconut flour because not only is it low carb and magnificently healthy, but it also absorbs plenty of liquid. Together with the protein powder, it is the ideal binder.
You can use crunchy or smooth peanut butter in this recipe, whichever you prefer. The bars with crunchy peanut butter can crumble a little when you cut them. If you are after razor-sharp edges, I recommend you use smooth peanut butter.
Always check the label when buying peanut butter to make sure it does not contain added sugar! I like to use the Meridian brand here in the UK - it contains 100% peanuts and nothing else.
You can add 1 teaspoon of cinnamon for a taste variation or a pinch of salt. If you're feeling a bit naughty, you could also add a handful of sugar free chocolate chips!Â
How long do homemade sugar free protein bars last in the fridge?Â
Your peanut butter bars will keep on the kitchen counter for a couple of days and a good 7 days in the fridge. You can also freeze them. What I love about them is that you can transport them easily. They are a perfect on-the-go snack.
Love peanut butter? Check out these recipes:Â
- Keto Chocolate Peanut Butter Fudge (Sugar Free Fudge)
- Low Carb Peanut Butter Cookies Recipe (Flourless)
- Grain Free Peanut Butter Granola (Sugar Free)
- Keto Peanut Butter Chocolate Bars
Tried these peanut butter protein bars? Give them a star rating below!
★ STAY IN TOUCH on FACEBOOK, PINTEREST and INSTAGRAM  for more great food and join my NEWSLETTER for the latest updates and a FREE EBOOK.★ Â
Peanut Butter Protein Bars
from Sugar Free LondonerNote: The servings slider only changes the first amount in each line and not any subsequent amounts. Please make your own calculations where necessary. ***As an Amazon Associate I earn from qualifying purchases.
Ingredients
Base Layer
- ½ cup / 130g peanut butter unsweetened
- 1 ½ tablespoon coconut flour
- 1 tablespoon protein powder
- 1 ½ tablespoon granulated erythritol
Top Layer
- ½ cup / 130g peanut butter
- 1 tablespoon cocoa powder unsweetened
- 1 ½ tablespoon granulated erythritol
- 1 tablespoon protein powder
- 1 ½ tbsp coconut flour
Instructions
- Preheat the oven to 175 Celsius / 350 Fahrenheit.
- Put the ingredients for the base and the top layer in separate bowls and mix with a fork, then knead with your hands to combine.
- Line a ovenproof dish with parchment paper. Spread the base layer, then add the top layer to fit a space of ca 5 x 6 inches.
- Bake for up to 25 minutes. The bars are ready when the top has set and is beginning to brown around the edges. Remove and let cool to room temperature before cutting.
Notes
Nutrition
This post contains affiliate links. If you click on one of these links and purchase a product, I may earn a small commission, at no extra cost to you. Thank you for supporting Sugar Free Londoner.
Mary
I prefer no chocolate so can I just double the base layer to make them?
Katrin Nürnberger
Of course!
Mary
Would it be possible to use peanut butter powder to reduce the fat?
Katrin Nürnberger
I don't think so because they'd just be dry and brittle.
Mary
I meant if I reconstituted the peanut powder to with water per instructions? Are coconut flour and almond flour interchangeable?
Thanks
Katrin Nürnberger
As a rule of thumb, you'll need to use about 3 x more almond flour than coconut flour. It is less absorbent. As for the peanut powder, you'd have to try it out and see whether it works. I have never used it. But since you'd be replacing fat with water, my guess is that the bars may turn out dry.
aidan
Hi, I'm new to keto so only learning. After reading the nutrition info do these bars work out roughly 40g each and 2 net carbs?
thank you
Aidan
Katrin Nürnberger
Hi Aidan, yes, these bars are 2g net carbs per bar. I did not weigh them.
aidan
Sorry Katrin, I thought I saw somewhere they were 40g each. I just made them but rather than make in a tray I used little cup cases to make individual portions. I always find that peanut butter no matter the brand is always a little bit clawing and coats the mouth and makes things dry at times. I found these to be a little dry (maybe under baked as took them out after 20 mins) but very very tasty. I love lots of things with peanut butter and these were delicious and will definitely be making them again. I also topped a couple with a little chocolate and god help me I could 3 or 4 at a time lol...Thank you
HEATHER VIRGINIA PETERSEN
pretty good and very easy to make!
Susan
What about powdered stevia? I'm type 1 diabetic so powdered stevia works best for me but confused on the conversion. Ty in advance!
Katrin Nürnberger
Hi Susan, you can use any sweetener as long as it is a 1:1 sugar substitute. It should say on the pack. I've had a few powdered stevia brands that are twice as sweet as sugar, so be sure you're not using too much.
Susan
Thank you!
Susan
What would the substitute be if I use almond flour instead?
Katrin Nürnberger
Use 3x more almond flour than coconut flour.
Damian
Hi, for the base recipes said granulated erythritol, is necessary grind it or not? I wish to do this bars asap, thank you.
Katrin Nürnberger
It's not necessary to grind it. But you can use powdered sweetener if you prefer. Both work just as well. I used a brown sugar alternative that is granulated.
Diana
Can I assume that the sugar listed is actually sugar alcohols since you are not using any added sugars? Thank you!
Katrin Nürnberger
No, I actually don't include the sugar alcohols at all because they are not processed by our bodies, making them essentially zero carb. The sugars you're seeing are from the other ingredients. Most foods contain some sugars from carbs.
Pam
What is the weight for the serving to equal the 211 calories?
Katrin Nürnberger
About 40 grams.
Magdalena
Hi I’d like to know what kind of protein powder you use.
Thanks
Katrin Nürnberger
Hi Magdalena, I use Pulsin Whey Protein Powder, I get it from Ocado.
Jenn
Is a pea protein okay? I try to avoid Whey due to issue with dairy. I know that will add a bit to carbs but it's what I have and know I can stomach 🙂
Katrin Nürnberger
I have never tried it, but it's worth a shot. I think they all behave similarly.
Dominic Hodges
Hi, I made these the other day and they have turned out very dry, not at all fudgey. I actually only cooked them for 20 minutes because I baked them in muffin cups instead of a baking tray.
Mine have come out at 3.6g net carbs according to Carb Manager which is a bit higher than I was hoping for, but also means I can't really put any sort of topping on them to help with the dryness.
They could really do with something like caramel between the two layers and/or a chocolate topping to moisten them up a bit, do you have any suggestions for that? I have 90% dark chocolate but I much prefer milk chocolate so don't really want to use that, especially as it will bump up the carb count a bit as well.
Katrin Nürnberger
I have a caramel recipe on my website, and you could make your own sugar free chocolate, too.
What a shame they turned out dry. It could have happened because your peanut butter was firmer than mine. When you buy a big tub, the top is always nice and soft, but if you don't stir it regularly, the bottom bits can get very firm. Also, if you bake it in individual containers such as muffin cups, consider reducing the oven time to as little as 12 -15 minutes as you would for cookies.
Dominic Hodges
Thanks Katrin, I did wonder about cooking time, but not until yesterday... I'll take a look at the caramel recipe. I've tried one before and it didn't work out too well.
Donna Read
Hello, I used Almond flour instead but kept to the same quantity as the Coconut flour. They turned out very dry, so much so that they just broke apart while slicing. They do taste nice though be them very hard to eat as they crumble up so much.
Wondering where I went wrong.
Katrin Nürnberger
Hi Donna, the reason could be that your peanut butter was firmer than mine. This would cause the end result to be drier. Another reason could be that your bars were flatter than mine. As a rule of thumb, the flatter a bake is, the less time it needs in the oven. I hope this helps and you can work out how to get your bars the perfect texture next time round.
SN07
Hi there,
I have not tried this recipe yet. I am just wondering based on the ingredients listed what is the net carb per slice?
Katrin Nürnberger
My nutrition panel always shows the total carbs and the fibre. For the net carbs, you deduct the fibre from the total carbs.
Karen Stinson
Where do you get Lily's? I live in France and can't even get them on Amazon.
Katrin Nürnberger
Hi Karen, I had a big batch brought over from the States. But when I run out, I just use the 90% chocolate by Lindt or make my own.
Susan Yakus
I am anxious to try these. They sound delicious! I have Vanilla Protein Power on hand. Will that taste ok? I also Chocolate Protein Powder.
Katrin Nürnberger
Hi, you could use either but check if it contains any sugar or sweeteners first. Mine was unflavoured and you may have to adjust the sweetness.
Marjie Bass
Is it possible to double this recipe?
Katrin
Yes, I don't think that would be a problem! If you bake it all at once, it may take a little longer in the oven.
Avery
Just checking, the baking dish needs to be 5x6 inches? Thanks!
Katrin
Yes, that's the size of dish I used. If yours is larger, just build a divider from aluminium foil, otherwise your bars will be too flat.
Betsy
Can I use powdered peanut butter in this recipe?
Katrin
I think that powdered peanut butter is fat reduced so you would not achieve the same taste.
Rico
Looks like basically no carbs (figuring in the sugar alcohol). I like to try and preserve as muscle as I can while on Keto. For taste, would I have to alter the other ingredient for taste it I doubled the protein? If so, what do you suggest?
Katrin
That's a good question. You'd add quite a bit more powder, which may make the bars brittle and dry-tasting. I'd add just a little more if you want (amount will depend on how liquid your peanut butter is).
CK
i've made these and they are tasty but very very flat - they do not look like the picture at all! And there wasn't really enough for 8 large slices as appear in your images. Did I do something wrong?!
Katrin
Hi Chrissy, if you use the amounts stated in the recipe you should end up with the same amount of bars I did. It's a lot of peanut butter we're using! However, if you're using peanut butter that's quite liquid it's possible that it spreads out more. Is this what you're referring to?
Pam
I made these protein bar s and they came out perfect and look like the picture you have. I love the taste too
Katrin
I’m so glad you liked them!
Debbie
Mine were very tasty but so dry you could hardly get them down. There was no need to knead. The mixture was pretty soft. Did I do something wrong?
Katrin Nürnberger
It's possible that they were in the oven a little too long. If the mix was nice and soft, that's the most likely reason.
Rebecca :)
Hi, I've just made these but the mixture never 'glistened' to start with, so quite hard to tell when they had been baked enough! They're also quite dry. I substituted agave syrup for the sweetener (just did like for like, so 1.5 tbsp agave syrup instead of the brown sugar substitute) so if anything I'd have thought it should have been wetter pre-bake and gooier post-bake? I used Whole Earth organic crunch peanut butter, and the protein powder was a flavoured one from MyProtein. Would be very grateful for any tips on where you think I went wrong with consistency? Thank you 🙂 They taste great, just dry!
Katrin
Hi Rebecca, so sorry you had problems with the recipe! I think it's probably down to the consistency of your peanut butter. I always have a litre pot of Meridian peanut butter. The oil tends to collect on top, so if you don't stir it up properly, you'll end up with really hard and crusty peanut butter at the bottom. If your peanut butter is hard to start with, you need to adapt the recipe and use less dry ingredients. I hope this helps and you will give it another go one day 🙂
Rebecca
HI Katrin, thanks v much for your reply. I bought the Meridian smooth peanut butter today and it's SO much wetter/more oily than the Whole Earth pb so Round 2 should be the right consistency - thanks for the advice. 🙂
Katrin
you're welcome Rebecca!!
Munchie
Hi, I would like to try making the peanut butter bars but you use erythritol which doesn’t agree with me (IBS). Can you please suggest an alternative sweetener? Thank you!
Katrin
You can replace it with any sweetener that works for your condition.
Fiona
Hi,I want to try these out but I'm not sure which protein powder to use. I'm guessing unflavoured would mean I can use it in different recipes but does say chocolate work better here?
Katrin
Hi Fiona, I think unflavoured protein powder is more versatile. You can add it to smoothies and also to granola for an extra protein boost. If you like the bars extra chocolatey, just add more cocoa powder 🙂
Fiona
Thanks Katrin, so glad I found your site. I really struggle to find gluten free recipes that aren't hugely com pled but still taste of sadness. I can't wait to try these out ☺
Christy
I tried making these for the first time tonight and the flavour was fantastic but I found the consistency a little too soft (they were similar to the inside of a peanut butter cup). I did swap out the coconut flour for almond flour and increased it to 3tbsp. I also noticed my peanut butter seemed super liquidy so that may have been the cause. Any suggestions for how to make them a little more solid? Thanks!
Katrin Nürnberger
The rough conversion from coconut flour to almond flour is x3, so next time try using a little more. Also, the consistency of the peanut butter will have an impact - the more liquid it is, the more flour you'll need to make the bars firmer. I'm sure next time you'll get the to be just right 🙂
Maeve
Can you use coconut sugar instead of granulated erythritol? 🙂
Katrin
Yes, absolutely!
Megan
What can i substitute the coconut flour with, I'm allergic to any coconut products.
Thank you
Megan
Katrin
Hi Megan, I'd replace it with 3 tbsp almond flour.
Dawn
I am trying to work out how many pieces this makes to calculate the calories. Can you advise?
Katrin
I always calculate the nutrition per portion. I cut 8 pieces, so the calories are stated per protein bar/= 1 portion. They are filling, so you could also cut into 16 squares and halve your calories.
Desiree Currie
My daughters kindergarten is 'peanut free' - do you think this recipe would hold together as well with almond or cashew butter for example? If not I'll still make it - as an afternoon/home snack
Katrin
Yes, absolutely. Sometimes my almond butter is more liquid than peanut butter. If you cannot knead the "dough" without getting sticky hands, just add an extra 1/2 tbsp of coconut flour. Alternatively, you can also leave the mix in the oven for longer.
Colleen Schoneveld
to Desiree. If your child's school is "Peanut free" they actually mean "Tree nut free" as well.
The best substitute for peanut butter is Sunflower butter. Though it is expensive.
Ruth Gallagher
what can i substitute for the protein powder plz?
Katrin
Hi Ruth, I would try with either 1 tbsp almond flour OR an additional 1/2 tbsp coconut flour - but I haven't tried this myself. I think this recipe can handle all kinds of substitutions. All you want is to make sure your mix does not get too dry. The bars will still taste good, but they will become brittle and crumbly.
Ruth Gallagher
thanks so much, going to make these over the weekend
Scally Wag
Hi.... these look great! Can you use an extra tblsp if coconut flour instead of protein? Im not keen! Or is there anotjer alternative? Thanks!
Katrin
I would try 1 tbsp almond flour or 1/2 tbsp coconut flour instead of the protein powder. Coconut flour absorbs so much liquid, probably more than protein powder. You don't want your mix to get too dry. But that will also depend on how liquid your peanut butter is. It'll be a bit of trying out.
Elyse
Do you have to use whey protein or can you use a plant-based one? I have a plant-based protein powder that I would like to use instead of going out to but yet another powder.
Katrin
Of course, you can use any protein powder in this recipe.
Elyse
Perfect! Thx!